Error Code P0619: Alternative Fuel Control Module RAM/ROM Error

Error Code P0619 is defined as Alternative Fuel Control Module RAM/ROM Error, meaning there’s a problem in the alternative fuel control module RAM/ROM, likely caused by its malfunction, or faulty wiring within the CAN bus harness.

This code is a generic trouble code, meaning it applies to all vehicles equipped with the OBD-II system, especially those made since 1996 up to present. This includes vehicles from, but not limited to, Chrysler, Dodge, Ford, etc. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.

However, this code is exclusive to vehicles that use alternative fuels like natural gas and electricity for propulsion.

When Error Code P0619 is stored, this means the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes), has seen a malfunction in the AFCM (Alternative Fuel Control Module). This problem has occurred in the random access memory (RAM)/read-only memory (ROM) portion of the AFCM.

A single module, increasing the efficiency of the controller and saving automakers space and money.

The KAM works by allowing the PCM and other controllers to keep data even when the ignition is turned off, or the battery is briefly interrupted.

Every time the ignition is turned on and the PCM is energized, multiple controllers perform self-tests. Aside from running internal controller self-tests, the CAN (controller area network) is used to compare signals from the individual module, ensuring various controllers are working and interacting properly.

If a problem is detected when monitoring AFCM/PCM KAM capacity, then Error Code P0618 will be stored, and simultaneously activating the Check Engine light. Depending on the severity of the problem, it may take multiple drive cycles for the Check Engine light to light up.

Common Symptoms

This code causes vehicle drivability issues, such as:

Stalling while idling

Slow acceleration

Harsh shifting

Increase in fuel consumption

Delayed engine cranking (especially when cold)

Other stored code may be present

Possible Causes

Common causes for this code include:

Malfunctioning AFCM

Shorted or open wires in CAN

Corroded, damaged, or loose connectors in CAN bus harness

Loose or damaged ground strap or ground wire in the control module

Insufficient control module ground

Defective CAN bus

How to Check

This code is one of the many tricky codes to diagnose and fix, even with professional technicians. Also, reprogramming issue must also be considered. Without the right reprogramming equipment, it will be impossible to replace a defective controller and complete the repair.

If there are other AFCM/PCM codes present, then they must be addressed first before diagnosing P0169

Start the diagnosis by connecting the OBD-II scanner, read the codes stored in the PCM and see if any related codes may be the root of the problem. After reading all saved codes, do a visual inspection of all circuits and wirings. Check the connectors and wirings using an ohmmeter to ensure there are no open or short circuits.

Then, check the PCM, CAN bus, and other relevant components.

When trying to diagnose this code, refer to your information source or TSB (technical service bulletin); looks for signs and symptoms parallel to the stored code. Search for the year, make, model, and engine of your vehicle. If you can find the right TSB, then you may get the best diagnostic information about your problem.

Then, use the DVOM to the test controller power supply fuses and relays. Next, test and replace any blown fuses as necessary. Fuses must be tested with circuit loaded.

If all fuses and relays are running well, check whether the controller related wiring and harness are in order. You may also want to check chassis and engine ground junctions. Again, use your vehicle information source to obtain ground locations as related circuits. Test ground integrity using the DVOM.

Then, check the system controllers for any signs of water, heat, or collision damage. Any controller that is damaged, especially by water, is considered defective and must be replaced.

If controller power and ground circuits are intact, then there’s a good chance the controller is defective, or there’s a programming error in the controller. Thus, controller replacement requires reprogramming. In some cases, you may want to get aftermarket reprogrammed controllers. Some vehicles and controllers require on-board reprogramming that may be done only through the dealership or a qualified shop.

How to Fix

Depending on your diagnosis, common repairs for this code include:

Replacement of the AFCM

Replacement of damaged wires, connectors, and fuses in the module

Replacement of ground straps and ground wires

Replacement of wires and connectors in the CAN bus

Replacement of the CAN bus (rare)

When left unfixed, this code could lead to engine misfires, acceleration problems, increase in fuel consumption, and could potentially damage the engine. Thus, it must be addressed as soon as possible.